Recent years have seen increased interest in environmental and pollution control. In this connection, frequently, it is desired to trace the origin of effluent materials. Thus, for example, it may be desired to identify factories and other sources of gaseous borne particulate pollution, such as those commonly referred to as smoke, aerosols, hazes, mists, and "smog". This may be of particular interest for example, as to electric or steam power generating plants, incinerators, or the like, burning wood, oil, gas, coal, synthetic fuel, processed or raw garbage, sewage sludge or refuse-derived fuels, and/or where several sources are so close to each other that their smoke or other gaseous particulate effluents are co-mingled, and it is desired to identify exactly which source among several is of particular interest. For example, one industrial plant in a group may be emitting particularly noxious, poisonous, otherwise objectionable materials as a combustion by-product, as a result of a process leak, or otherwise, and for policing purposes it is desired to identify exactly which among several sources having similar effluents is the source. Conversely, one source among several may wish to establish that it is not the origin of offensive constituents. Environmental considerations aside, it may simply be desired to achieve other results, such as monitoring a specified source for production efficiency. Another related area of interest is in tracing the atmospheric movements of specific air masses, per se as well as insofar as they may be carriers of such particulate pollutants.
It has been proposed to use radioactive materials for the positive tracing of sources in such situations, but these are now generally disapproved because, although they survive the combustion process itself, there is increased awareness of the dangers of the indiscriminate exposure of humans and other living things to radiation.
Accordingly, it is an object of this invention to provide means to trace the source of the gaseous borne particulate matter.
Another object of this invention is to provide such means in a manner which may be identified with its source.
Yet another object of this invention is to provide such means without disbursing radioactive materials.